N-(2-pyrrolidinonyl) methyl carbamate derivatives

ABSTRACT

Compounds having the formula   D R A W I N G wherein n is 1 or 2 and R is a monovalent or divalent aliphatic, alicyclic or aryl radical produced by the reaction of n moles of an isocyanate or diisocynate with n moles of N-hydroxymethyl-2pyrrolidinone and uses thereof.

United States Patent [1 1 Freyermuth et a1.

[ Sept. 2, 1975 N-(l-PYRROLIDINONYL) METHYL CARBAMATE DERIVATIVES [75] Inventors: Harlan Benjamin Freyermuth;

David I. Randall, both of Easton,

[21] App]. No.1 248,021

[52] US. Cl. 260/326.25; 260/326.43; 260/999;

71/95 [51] Int. Cl C07d 27/08 [58] Field of Search 260/3263, 326.43, 326.25

[56] References Cited UNITED STATES PATENTS 2,700.039 1/1955 Ehrhart et a1 260/2391 2,945,863 7/1960 Buc et a1 260/3263 3,001,955 9/1961 Taub 260/25 3,073,834 1/1963 Bortnick.. 260/294 3,287,471 11/1966 Cusic 260/3263 3,370,079 2/1968 Horlein 260/3263 3.449.360 1/1969 Mizzoni 260/313.1

FOREIGN PATENTS OR APPLICATIONS 576,465 5/1959 Canada 260/3263 OTHER PUBLICATIONS Wagner et al., Synthetic Organic Chemistry, Wiley and Sons, 1953, New York, p. 645.

Primary Examiner-Joseph A. Narcavage Attorney, Agent, or Firm-Walter C. Kehm; James N. Blauvelt [5 7] ABSTRACT Compounds having the formula wherein n is 1 or 2 and R is a monovalent or divalent aliphatic, alicyclic or aryl radical produced by the reaction of n moles of an isocyanate or diisocynate with n moles of N-hydroxymethyl-2-pyrro1idinone and uses thereof.

13 Claims, No Drawings N-(Z-PYRROLIDINONYL) METHYL CARBAMATE DERIVATIVES BACKGROUND OF THE INVENTION This invention relates to novel derivatives of N( 2- pyrrolidinonyl carbamate, a method of making same and uses thereof.

Among the various materials known in the art as being plant growth regulators, the derivatives of phosphonic acid are currently enjoying prominence. It has now, however, been found that a group of derivatives of N-hydroxymethyl pyrrolidinone, specifically certain monovalent or divalent aliphatic, alicyclie or aryl radical substituted derivatives thereof, have unique biological activity in that they exhibit plant growth regulation by effectively inhibiting the flowering of plants. The aforesaid derivatives are also useful as pharmaceutical agents and an intermediates for dyestufis.

The reaction product of phenyldiisocyanate and 2- pyrrolidinone as well as the products obtained from reaction of m-phenylenediiosocyanate and hexamethylene diisocyanate and 2-pyrrolidinone are known in the art. The preparation N-hydroxymethyl-Z-pyrrolidinone is also known. It has not, however, been reported in the art that the reaction of an isocyanate with an N- hydroxymethyl-Lpyrrolidinone and that the derivatives will be useful as described above.

SUMMARY OF THE INVENTION It is accordingly an object of this invention to provide derivatives of N-hydroxymethyl-Lpyrrolidinone.

It is another object of this invention to provide for such derivatives, methods of preparation thereof and uses therefor, such as the application to plants as plant growth regulators.

It is still another object of this invention to provide for such derivatives for use as pharmaceutical agents and as intermediates in the synthesis of dyestuffs for synthetic fibers.

It is still another object of the instant invention to obviate one or more drawbacks of the prior art.

Other objects and advantages of the present invention will become apparent as the description thereof proceeds hereinafter.

In satisfaction of the foregoing objects and advantages. there is provided by this invention, derivatives of N-hydroxymethyl-Z-pyrrolidinone of the following formula:

wherein R is a substituted and unsubstituted phenyl, said substituted phenyl being substituted by nitro or one or two chloro atoms; substituted and unsubstituted C -C alkyl. said substituted alkyl being monosubstituted by chloro; and naphthyl and n is l or 2. These compounds are synthesized by the reaction of II or 12/2 moles of an isocyanatc and 11 moles of N- hydroxymethyl-Z-pyrrolidinone.

lt is known that it is characteristic of most carbamate derivatives to generate gas and evolve carbon dioxide at their melting points. For this reason, they are useful asblowing agents where it is of interest to generate an inert gas at an elevated temperature. Thermal decomposition by VPC yields fractions which are analyzed by IR and which indicate that besides carbon dioxide, several organic products are obtained. Decomposition with the evolution of carbon dioxide normally leaves a colorless liquid, the composition of which has not been completely determined.

The carbamate derivatives herein described are conveniently prepared by the reaction of an isocyanate or diisocyanate with N-hydroxymethyl-2-pyrrolidinone.

In carrying out the reaction, any isocyanate may be used, the only requirement being that it does not have reactive substituents such as hydroxy or amino groups. The choice of isocyanate will determine the derivative produced; preferred are substituted and unsubstituted phenyl isocyanates, diisocyanates and substituted and unsubstituted aliphatic isocyanates. Exemplary are pbromophenyl isocyanate, butyl isocyanate, tert.-butyl isocyanate, 2'chloroethyl isocyanate, o-chlorophenyl isocyanate, m-chlorophenyl isocyanate, pchlorophenyl isocyanate, 2,5-dimethylphenyl isocyanate, dodecyl isocyanate, ethyl isocyanate, hexamethylene diisocyanate, hexyl isocyanate, methylene-di-p phenyl, diisocyanate, methyl isocyanate, l-naphthyl isocyanate, o-nitrophenyl isocyanate, m-nitrophenyl isocyanate, p-nitrophenyl isocyanate, octyl isocyanate, p-phenylazophenyl isocyanate, phenyl isocyanate, ptoluenesulfonyl isocyanate, tolylene-Z,4-diisocyanate, o-toly isocyanate, m-tolyl isocyanate, p-tolyl isocya nate, trichloroacetyl isocyanate.

The aforementioned compounds include those in which the monovalent or divalent aliphatic, alicyclic or aryl radicals may be monoor di-substituted.

As examples of the foregoing there may be men tioned the C alkyl, aryl or alicyclic radicals wherein there is mono-, dior tri-substitution thereon, i.e., halo, or nitro substituents. For example, fluorine, chlorine, bromine, and iodine, chlorine being preferred. For example, bicyclohexyl, butylcyclohexane, cyclododecane, 1,5,9-cyclododecatriene, cyclododecene, cyclohexane, cyclohexene, l,5cyclooctadiene, cyclooctane, cyclooctene, decahydronaphthalene, decane, di-isobutylene, 1,3-dimethyladamantane, 2,5-dimethyl-2,4- hexadiene, diphenylacetylene, 1,6-diphenyll ,3,5- hexatriene, dodecane, dotriacontane, eicosane, 3- ethyl-Z-pentene, heptane, hexacosane, hexadecane, hexane, hexatriacontane, isoprene, ligroin, (+)-limonen, 2-methylbutane, 2-methyl-2butene, methylcyclohexane, 4-methylcyclohexene, nonane, octacosane, l-octadecene, 1,7-octadiene, octane, octene-( l and 2), pentane, pentene, Z-phellandrene, lphenylheptane, l-phenylnonane, l-phenylpentadecane, l-phenyltetradecane, l-phenyltridecane, lphenylundecane, pinene, squalane, tetra-iso-butylene, tctracosane, tetradecane, 2,6,10, l4-tetramethyl-pentadecane, tetraphenylethylene, triiso-butylene, tricosane, l,5,9-trimethylcyclododecatriene, 2,2,4-trimethylpentane, undecane, benzene, benzylbiphenyl, bibenzyl, biphenyl, butylbenzene, iso-butylbenzene, sec.butylben7.enc, tert.- butylbenzene, p-tert.-butyltoluene, cumene, p-cymene, p-di-terL-butylbenzene, p-dicyclohexylbenzenc, diethylbenzene, l,4-diphenyl-l ,3-butadiene, l, l diphenylethylenc, diphenylmethane, di-isopropylbcnzene, ethylbenzene, hexaethylbenzcne, hexamethylbenzene, hcxaphenylbenzene, indene, mesitylene, a-methylstyrene, l,2,3,4,5,6,7,8- octahydroanthraccne, pentamethylbenzene, pentylbenz( a)anthracene, dimethylnaphthalenc, 9- methylanthracene, 3-methylcholanthrene, lmethylnaphthalene, 2-methylnaphthalene, naphtha cene, naphthalene, 2,5-norbornadienc, phenanthrene, pyrene, tetradecahydrophenanthrene, 5,6,1l,l2-tetra phenylnaphthacene, triplycene.

As an example of the halogen substituted radicals, there may be mentioned: 9,lO-bis(chloromethyl)anthracene, 1,-4 bis (chloromcthyl )cyclohexane, lbromobutane, 2-bromobutane, l-brorno-Z- chloroethanc, bromochloromethane, l-bromo-echloropropane, 2-br0mo-1-chloropropane, bromocyclohexane, bromocyclopentane, l-brornodecane, lbromododecane, 1bromoeicosane, bromoethane, bromoform, l-bromohepatadecane, l-bromohepatane, 1- brornohexadecane, l-bromohexane, bromomethane, l-bromo-3-methylbutane, 3-(Bromomethyl)hcptane, 2-bromo-4-methylpentane, 3-(bromomcthyl)pentanc, l-bromo-Z-methylpropane, 2-bromo-2-methylpropane, l-bromononadecane, l-bromononane, lbromooctadecane, l-bromooctane, 2-bromooctane, l-bromopentadecane, l-bromopentane, lbromopropane, 2-bromopropane, 3-bromopropene, l-bromotetradecane, bromotrichloromethane, 1- bromotridecane, l-bromoundecane, a-bromo-mxylene, carbon tetrabromide, carbon tetrachloride, lchlorobutane, chlorocyclohexane, l-chlorodecane, lchlorododecanc, 1 -ch1oroeicos, chloroethane, 1-chloroethyl)benzenc, chloroform, l-chlorophetane, l-chlorohexadecane, l-chlorohexane, 1-chloro-3- methybutane, 2-chloro-2-methylbutane, l-ch1oro-3- methyl-Z-butanc, 4-chloromethyll .2- dimethylbenzene, 3-(chloromcthyl)heptane, 2-chloro-4-methylpentane, 3-(chloromethyl)pentane, 1-chloro-2-mcthylpropane, 2-chloro-2 -mcthylpropane, l-chlorononane, l-chlorooctadecane, 1 chlorooctanc, l-chloropcntanc, l-chloropropane, 2- chloropropane, 2-chloropropane, 3-chloropropcne, 1- chlorotetradecanc, a-chlorotolucne, lchlorotridccanc, 1-chloroundecane, a-chloro-o-xylene,

1,2-dibromobutanc, 1,3-dibromobutanc, 1 ,4- dibromobutane, 2,3-dibromobutane, trans-1,4- dibromo-Z-butene, l,l()-dibromodecanc, 1,2-dibromo- 1,l-dichloroethane, l, l -dibromoethane, 1,2- dibromoethanc, 1,2-dibromohexane, 1,6- dibromohexanc, dibromomethane, l,2dibromo-2- methylpropane, 1,5-dibromopentanc, l ,2- dibromopropanc, 1,3-dibrompropane, 2,3- dibromopropene, 1,l4-dibromotetradecanc, l ,1- dichlorobutane, trans-1 ,4-dichloro-2-butene, 1, l dichlorodecanc, 1,1-dichloroethane, 1,2- dichloroethane, 1,2-dichl0roethanc, cis- 1 ,2- dichloroethylenc, trans-1 ,2-dichloroethylenc, 1,2-

dichlorocthylene, 1,6-dichlorohexanc, dichloromethanc, 1,5-dichloropentane, 1,2-dichloropropanc, 1,3- dichloropropane, 2,3-dichloropropenc, o,m-

dichlorotoluene, o,p-dichlorotol uenc, diiodomethane, l ,5-diiodopcntane, 1,3-diiodopropane, lfluorodecanc, l,fluorohexane, 1,1,1,2,3,3,3-heptachloropropanc, l,- 2,3,4,5,6-hexabromocyclohexane, hexachlorol ,3- butadtene, l,2,3,4,5,6-hexachlorocyclohexane,( 2- isomer) hexachloroethane, a,a,a,a',a,a-heXachloro-pxylene, l-iodobutane,2-iodobutane, iodocyclohexane, 10iododecane, l-iodododecane, iodoethane, iodoform,

l iodoheptane, l-iodohexadecane, l -iodohexane, iodomethane, l-iodo-3-methy1butane, l-iodo-2- mcthylpropane, 2-iodo-2-methylpropane, iodooctadecane, l-iodooctane, 2-iodooctane, 1- iodopentane, l-iodopropane, 2-iodopropane, 3 iodopropcne, mcthallyl chloride, a,a,a,2,4- pentachlorotoluene, 1 ,2,3 ,4-tetrabromobutane,

l, l ,2,2-tetrabromoethane, a,a,a',a'-tetrabrom0-oxylene, 1 1 ,2,2-tetrachloroethane, tetrachloroethane, tetrachloroethylene, a,a,a,a-tetrachlorololuene, tribromoethylene, 1,2,3tribromopropane, l ,l,1- trichloroethane, l l ,2-trichl0roethane, trichloroethylene, l ,2,3-trichloropropane, bis( pchlorophenyl )mcthane, bromobe nzene, 4- bromobiphenyl, l-bromo-3-chlorobenzenc, 4-bromol ,Z-dichlorobenzene, l-bromo-4-f1uorobenzenc, l-bromo-Z-iodobenzene, l-bromo-3-iodobenzene, l-bromo-4-iodobenzene, 2-bromomesitylene, lbromonaphthalene, 2-bromonaphthalene, 3-bromol ,2,4,5tetramethylbenzene, o-bromotolucne, mbromotoluene,p-bromotoluene, m-bromo-a,a,atrifluoro-toluene, bromotriphenylethylene, 4-bromom-xylene, 2-bromo-p-Xylene, chlorobenzene, pchlorocumene, 1-chloro-2-fluorobenzene, l-chloro-3- fluorobenzene, l-chloro-2-iodobenzcne, l-chloro-3- iodobenzene, l-chloro-4-iodobenzene, 1

chloronaphthalene, 2-chloronaphthalene, pchlorostyrene, o-chlorotoluene, m-chlorotoluene, pchlorotolucne, 2chloro-pxylene, 4-chloro-o-Xylene,

difluorobenzene, o-diiodobenzene, m-diiodobenzene, p-diiodobenzene, diphenyliodonium bromide, fluorobcnzene, l-fluoronaphthalene, o-fluorotoluene, mfluorotolucne, p-fluorotoluene, hexachlorobenzene, hexaiodobenzene, iodobenzene, 4-iodob1pheny, l-

iodonaphthalenc, o-iodotoluene, m-iodotoluene, piodotoluene, 2iodo-m-xylene, 4-iodo-m-xylene, 2- iodop-xylene, 2,2,2,2,4-pcntachlorotoluene, l,2,4,5tetrabromobenzenc, l,2,4,5-tetrachlorobenzene, tctrachlorotctrahydronaphthalene, 2,22,6- tctrachlorotoluene, 2,2,2,2-tetrachlorotolucnc, 1,2,4-

tribromobenzcnc, l,3,5tribromobenzene, 1,2,4- trichlorobenzene, l,3,5-trichlorobenzene, 1,1,1- trich1oro-2,2-bis( p-chlorophenyl )ethane, 2,2,4-

trichlorotoluene, a,3,4-trichlorotoluene.

DESCRIPTION OF THE PREPARED EMBODIMENT The carbamatc derivatives of this invention may be attained by reacting n or n/2 moles of N- hydroxymethyl-Z-pyrrolidinone with 1 mole of the aforementioned isocyanates or diisocyanates.

The N-hydroxymethyl-2-pyrrolidinone starting material may be obtained in relatively good yields by the re action of 2-pyrrolidinone with paraformaldehyde in the presence 'of a small amount of an alkaline catalyst such as potassium hydroxide. The preparation of the precursor is discussed in detail in US. Pat. No. 3,073,843.

Broadly speaking, the instant invention includes the provisions of a compound having the formula:

wherein R is a monovalent or divalent aliphatic, alicyclic or acyl radical and wherein n is l or 2.

The aforementioned derivatives have been found to provide unexpectedly increased flower inhibition properties in that they effectively retard the flowering of plants such as green plants and the like, and thereby serve as an effective herbicide in decreasing the foliage or retarding the growth thereof. The instant comto unds are believed to be effective by virtue of the fact that they are absorbed by the plant and thereafter release a plant flowering inhibiting agent, in a form in which it is used by the plant.

The compounds of this invention are soluble in varying degrees in water and accordingly they can be applied to the plant in increased solutions composed wholly or partially of water; partial solutions include those formed of water and acetone or methylethyl ketone. Any aqueous medium may be provided that is not itself toxic to the plant. In the case of those particular derivatives which have relatively low water solubility, they may be solubilized by the use of co-solvents and the like. Also, the compounds may be absorbed on solid carriers such as vermiculite, attaclay, talc and the like for application in granular form. Dusts may also be used in which case the active ingredients will be diluted with clays or other powders, i.g., pyrophyllite, diatomaceous earth and attapulgitc.

It has also been found that as an agricultural chemical, the compounds are useful as crop insecticides, as soil systemic and foliar fungicides, as preand postemergent aquatic weed inhibitors, as nematocides and as insecticides for noncrop insects such as house flies.

The compounds of this invention can be applied to the plants or to grassy land in a concentration of from 1 to 20 lbs. per acre on higher, dependent on the particular derivative used. A preferred concentrate of application ranges from 2 to lbs. per acre. The derivatives are generally only applied to key plants in a low volume of water ,to achieve satisfactory inhibition, and this is an important advantage of this invention. On the other hand. it is necessary to apply known agents in order to achieve the same effect in large volumes of water. of the order of 200 to 400 gallons per acre, even up to 1,000 gallons per acre to achieve initiation. It is accord ingly possible to apply the compounds of this invention in far lower volumes of water to achieve a satisfactory flower inhibition. The ability to apply the instant compounds and reduce the high level of water ordinarily needed is a great agronomic advantage, because a large acreage of plantation can now be treated before re course to water supply is necessary, smaller equipment can be used and costs can be reduced generally.

The foregoing derivatives of the N-hydroxymethyl-Z- pyrrolidinone may be obtained by the reaction of an isoeyanate or diisocyanate with the N-hydroxymethyl pyrrolidinone usually in the absence of a catalyst, however, in some instances an alkaline catalyst such as N- methyl or N-ethylmorpholine is helpful. The carbamate reactions are exothermic and even though a solvent is not necessary one may wish to employ an inert organic solvent such as acetone, dioxane, diethylcarbitol, chlo roform, carbon tetrachloride, benzene, dimethyl formamide, n-methyl-Z-pyrrolidinone and the like.

The reaction which is a condensation reaction, may be conveniently carried out in one of the aforementioned solvents, such as acetone, inasmuch as both reactants (N'hydroxymethyl-2-pyrrolidinone and the isoeyanate) are normally quite soluble in ketone solvents. When acetone is used, the carbamate derivatives may precipitate out and thereafter be isolated by conventional filtration methods. lf this is not the case, the earbamate derivatives may be isolated by conventional evaporation methods, i.e., by evaporating the acetone or by dilution with water or an organic solvent in which the carbamate is not soluble.

The reaction is generally conducted at low temperatures and preferably in an inert solvent which has had substantially all the water removed therefrom. Preferred temperatures of operation are about 45 to about C and optionally as low as about 35 to as high as C. A preferred solvent for use in the invention is acetone although other equivalent solvents may employed, such as those mentioned hereinabove.

In conducting the process, the isocyanate, diisocyanate or phenylisocyanate, a derivative or substituted form thereof, in solvent solution, is generally gradually charged to a solution containing the N-hydroxymethyl- Z-pyrrolidinone also in a solvent. The gradual addition is conducted with stirring at the desired temperature, as aforesaid. After all the materials are added at the lower temperature, the reaction mixture which is exothermie soon begins to reflux. The mixture is refluxed for a short time: about 10 minutes to about minutes, preferably 20 minutes, and then allowed to go to completion after which it is allowed to cool. Thereafter a precipitate forms which is filtered, washed and dried.

The following examples are presented to further illustrate the invention but are not considered to be limit ing. All parts and proportions of the following examples as well as in the appended claims are by weight unless otherwise specified.

EXAMPLE 1 A solution of 12 g. of phenylisocyanate in 50 ml. acetone is added gradually to a solution of l 1.5 g N- hydroxymethyl-2-pyrrolidinone in 50 ml. acetone with continual stirring at a temperature of 50C. The reaction is exothermic and the acetone soon begins to reflux. The mixture is refluxed on the steam precipitated crystalline carbamate, is filtered, washed twice with 50 ml. of acetone and dried in an oven at 55C. The produet, N-phenyl2-pyrrolidinoyl methyl carbamate weights 17.1 g. and melts at 94- 96C with the evolution of carbon dioxide.

EXAMPLE 2 A solution of 2-chlorophenylisocyanate and 50 ml. acetone is added over a period of minutes to a warm (50C) solution of 1 1.5 g. N-hydroxymethyl- 2pyrrolidinone in 50 ml. acetone. After the addittion is complete, the mixture is refluxed for one hour. Evaporation of one-half of the acetone on a steam bath and cooling gives a white precipitate: N2-chlorophenyl-2- pyrrolidinonyl-methyl carbamate,

which melts at 200 201C with the evolution of gas. The remainder of the acetone is evaporated leaving an oil which may be a geometric isomer.

EXAMPLE 3 Fifteen grams of 3-chlorophenylisocyanate is gradually added to a solution of 1 1.5 g. N-hydroxymethyl-Z- pyrrolidinone in 100 ml. of acetone. After the addition is complete minutes), the mixture is refluxed for 1 hour. The hot solution is filtered and after cooling in an incewater bath, a white crystalline product separates. After filtering and drying in an oven at 55 60C, the

product, N-3-chlorophenyl-2-pyrrolidinonylmethyl carbamate,

H O 1 ll & N-C-O-CH. ,N

weighs 14.3 g. and melts at 142 143C with the evolution of carbondioxide.

EXAMPLE 4 weights 15.6 g., and melts at 146 147C with the evolution of carbon dioxide.

EXAMPLE 5 A solution of 8 g. Z-nitrophenylisocyanate in 30 ml. acetone is gradually added (5 minutes) to a warm (50C) solution of 5.75 g. N-hydroxymethyl-Z- pyrrolidinone in 50 ml. of acetone. After the exothermic reaction subsides, the mixture is refluxed for one hour, and then filtered. After cooling, the product, N-Z-nitrophenyl-Z- pyrrolidinonylmethyl carbamate,

is precipitated by dilution with water. The precipitated product after filtering and drying in an oven at 60C, melts at 107 108C and evolves carbon dioxide at EXAMPLE 6 Eight grams of 3-nitrophenylisocyanate is dissolved in 50 ml. acetone by warming on a steam bath. A solution of 5.75 g. N-hydroXy-methyl-2-pyrrolidinone in 50 ml. of acetone is made by warming on a steam bath and filtering from a small trace of insoluble material through fluted filter. The isocyanate solution is added gradually to the N-hydroxymethyl-2-pyrrolidinone solution over a period of 5 minutes. The mixture is then refluxed for one hour on an oil bath, during which time some small crystals separate. Cooling in an icewater bath causes further separation of crystals. These are filtered and dried in an oven at 60C. The product, N-3- nitrophenyl-2-pyrrolidinonyl-methyl carbamate melts at 144 145C with the evolution of carbon di I oxide and weighs 9.9 g.

EXAMPLE 7 A solution of 5.75 g. N-hydroxymethyl-Z- pyrrolidinone in 50 ml. of acetone is made by gently warming on a steam bath. '15 this there is gradually added a solution of 8 g. 4-nitrophenylisocyanate in 30 ml. of acetone over a period of 5 minutes. The mixture is refluxed on an oil bath for 1 hour, during which time some crystals separate. The mixture is cooled in an icewater bath and the crystals filtered and dried in an oven at 60C. The product, N-4-nitrophenyl-2-pyrrolidinonyl-methyl carbamate,

weighs 1 1.5 g. and melts at 144 145C with the evolution of carbon dioxide. A mixed melting point with the meta isomer described in Example 3 gives a 5 depression of melting point.

EXAMPLE 8 A solution of 18.5 g. 3,4-dichlorophenylisocyanate and 30 ml. of acetone is added gradually over a period of 5 minutes to a solution of 1 1.5 g. N-hydroxymethyl- 2-pyrrolidinone in 100 ml. of acetone. After the exothermic reaction has subsided. the mixture is refluxed for 1 hour. The hot solution is filtered and cooled in an icewater bath to precipitate the carbamate derivative. After filtering and drying in an oven at 60C the product, N-3,4-dichlorophenyl-2-pyrrolidinonylmethl carbamate,

HO Ill weighs 18 g. and melts at 134 14 135C with the evolution of carbon dioxide gas.

EXAMPLE 9 A solution of 16.5 g. l-naphthylisocyanate is added gradually over a period of 10 minutes to a solution of l 1.5 g. N-hydroxymethyl-2-pyrrolidinone and 60 ml. of acetone. The mixture is refluxed for 10 minutes on an oil bath. One-half of the acetone is distilled and after standing 0vernight,the product is separated by filtration and dried in a vacuum oven at 60C. The product, N- l -naphthyl-Z-pyrrolidinonyl-methyl carbamate,

weighs 23.5 g. and melts at 183 185C with the evolution of carbon dioxide gas.

EXAMPLE H c O weighs 1 1.5 g. and melts at 137 138C with evolution of carbon dioxide.

EXAMPLE 1 1 To a solution of l 1.5 g. N-hydroxymethyl-Z- pyrrolidinone in 100 ml. of acetone there is added over a period of ten minutes, 8.7 g. of 2,4- tolylenediisocyanate. The mixture is refluxed in an oil bath for one hour. The reaction mixture is filtered and the acetone evaporated on a steam bath, the white solid residue remaining is dried in an oven at 60C. The N-2.4-m-tolylene-bis (Z-pyrrolidinonyl-methyl carbamate),

weighs 11 g. and after purification by treatment with boiling ethanol, filtering and drying, melts at 160 162C with evolution of carbon dioxide.

EXAMPLE 12 The procedure of Example 1 l is repeated except that 8.7 g. of an 2,4 and 20% 2,6-tolylenediisocyanate isomer mixture is used. Evaporation of the acetone produces a viscous oil comprising a carbamate isomer mixture, This material gasses at 60C. An isomeric mixture of N-2,4-m-toluene-bis (2-pyrrodidinoyl-methyl carbamate), and N-2,6-m-toluene bis (2-pyrrolidinoylmethyl carbamate),

CH H0 (80% 2,4-isomer, 20% 2,6-isomer) is dried thoroughly in a vacuum oven at 60C.

EXAMPLE 13 A solution of 8 g. allyisoeyanate and 50 ml. acetone is added gradually to a solution of l 1.5 g. N- hydroxymethyl-2-pyrrolidinone in 50 m1. of acetone. The mixture is refluxed for one and one-half hours on a steam bath. After evaporation of the acetonean oily residue of N-Z-propenyl-2pyrrolidinonylmethyl carbamate,

having a repulsive odor remain.

EXAMPLE 14 A solution of 3,5 g. N-hydroxymethyl-2 pyrrolidinone in 50 ml. of acetone is heated to 50C and 5 g. trichloroacetylisocyanate is added dropwise over a ten minute period. The mixture is refluxed for 1 hour and the hot solution filtered through fluted filter paper. The acetone is evaporated and the product, an oily residue of N-trichloroacetyl pyrrolidinonyl-methyl carbamate,

is dried thoroughly in a vacuum oven at 60C.

EXAMPLE 15 To a solution of l 1.5 g. N-hydroxymethyl-Z- py'rrolidinone in 80 ml. of acetone there is added gradually over 5 minutes a solution of 7.1 g. ethylisocyanate and ml. of acetone. The mixture is refluxed for one hour and filtered while hot. The acetone is evaporated on a steam bath and dried in an oven at 60C. The product is a colorless oil, N-ethyl-2-pyrrolidinonylmethyl carbamate weighs 16.5 g. A sample is placed in a capillary tube and heated to 145C whereupon it decomposes and gives off carbon dioxide.

EXAMPLE l6 1 1.5 g. (0.1 mole) of N-hydroxymethyl-Z- pyrrolidinone is dissolved in 80 ml. of acetone by warming (50C) on a steam bath. There is gradually added 7.5 g. hexamethylene diisocyanate; 20 ml. of acetone is used as diluent for the diisocyanate. The mixture is refluxed for 1 hour on a steam bath, during which time a white crystalline solid separates out. After cooling in an ice bath, the bisurethane is filtered on a Buchner funnel, washed with acetone and dried in an oven at 55C. The product N-l ,6-hexamethylene-bis-2- pyrrolidinonyl-methyl carbamate,

We claim: 1. A compound having the formula I where n is l or 2 and R is selected from the group consisting of substituted and unsubstituted phenyl, said substituted phenyl being substituted by nitro or one or two chloro atoms; substituted and unsubstituted C,C alkyl, said substituted alkyl being mono-substituted by chloro; and naphthyl.

2. A compound as defined in claim 1 wherein R is phenyl or naphthyl.

3. The compound as defined in claim 1 which is N- phenyl-2-pyrrolidinonyl-methyl carbamate.

4. The compound as defined in claim 1 which is n-2- chlorophenyl-2-pyrrolidinonyl-methyl carbamate.

5. The compound as defined in claim 1 which is N-3- chlorophenyl-2-pyrrolidinonyl-methyl carbamate.

6. The compound as defined in claim 1 which is N-4- chlorophenyl-Z-pyrrolidinonyl-methyl carbamate.

7. The compound as defined n claim 1 which is N- 3,4-dichlorophenyl-2-pyrrolidinonyl-methyl carbamate,

8. The compound as defined in claim 1 which is N-2 nitrophenyl-2-pyrrolidinonyl-methyl carbamate.

9. The compound as defined in claim 1 which is N4- nitrophenyl-2-pyrrolidinonyl-methyl carbamate.

10. The compound as defined in claim 1 which is N- l-naphthyl-2-pyrrolidinonyl-methyl carbamate.

1]. The compound as defined in claim 1 where R is an alkyl having from 1 to 6 carbons.

12. The compound as defined in claim 1 which is designated N-trichloroacetyl-Z-pyrrolidinonyl-methyl carbamate.

13. The compound as defined in claim 11 designated N-ethyl-2-pyrrolidinonyl-methyl carbamate. 

1. A COMPOUND HAVING THE FORMULA
 2. A compound as defined in claim 1 wherein R is phenyl or naphthyl.
 3. The compound as defined in claim 1 which is N-phenyl-2-pyrrolidinonyl-methyl carbamate.
 4. The compound as defined in claim 1 which is n-2-chlorophenyl-2-pyrrolidinonyl-methyl carbamate.
 5. The compound as defined in claim 1 which is N-3-chlorophenyl-2-pyrrolidinonyl-methyl carbamate.
 6. The compound as defined in claim 1 which is N-4-chlorophenyl-2-pyrrolidinonyl-methyl carbamate.
 7. The compound as defined n claim 1 which is N-3,4-dichlorophenyl-2-pyrrolidinonyl-methyl carbamate,
 8. The compound as defined in claim 1 which is N-2-nitrophenyl-2-pyrrolidinonyl-methyl carbamate.
 9. The compound as defined in claim 1 which is N-4-nitrophenyl-2-pyrrolidinonyl-methyl carbamate.
 10. The compound as defined in claim 1 which is N-1-naphthyl-2-pyrrolidinonyl-methyl carbamate.
 11. The compound as defined in claim 1 where R is an alkyl having from 1 to 6 carbons.
 12. The compound as defined in claim 1 which is designated N-trichloroacetyl-2-pyrrolidinonyl-methyl carbamate.
 13. The compound as defined in claim 11 designated N-ethyl-2-pyrrolidinonyl-methyl carbamate. 